Dispatch function is added with test cases.

TODO.md

@@ -16,8 +16,13 @@
 * [x] Update path to modules and configuration in import.sh during installation.
 * [x] Add support for configuration file in other places than /etc.
 * [x] Add an Install section to README.
+* [x] Add dispatch function.
+* [ ] Add path module.
+* [ ] Add lock module.
+* [ ] Add is module.
 * [ ] Publish an article in Fedora Magazine.
 * [ ] Report bug in bash 5.1.0.
 * [ ] Ask bash developers for strict mode support, like in zsh, because it's critical for this project.
-* [ ] Add path module.
 * [ ] Use realpath instead of readlink -f, when possible.
+* [ ] Write a package manager for bash: bapt, for strict bash code only.
+* [ ] SPDX-License-Identifier: LGPL-2.1-or-later

bash-modules/install.sh

@@ -19,10 +19,10 @@ main() {
   echo "Bin directory: \"$BIN_DIR\"."
 
   mkdir -p "$MODULES_DIR" || { echo "ERROR: Cannot create directory \"$MODULES_DIR\"." >&2 ; return 1 ;}
-  install -vt "$MODULES_DIR" src/bash-modules/*.sh || { echo "ERROR: Cannot install modules to directory \"$MODULES_DIR\"." >&2 ; return 1 ;}
+  install -t "$MODULES_DIR" src/bash-modules/*.sh || { echo "ERROR: Cannot install modules to directory \"$MODULES_DIR\"." >&2 ; return 1 ;}
 
   mkdir -p "$BIN_DIR" || { echo "ERROR: Cannot create directory \"$BIN_DIR\"." >&2 ; return 1 ;}
-  install -vD src/import.sh "$BIN_DIR/import.sh" || { echo "ERROR: Cannot install import.sh script to \"$MODULES_DIR\"." >&2 ; return 1 ;}
+  install -D src/import.sh "$BIN_DIR/import.sh" || { echo "ERROR: Cannot install import.sh script to \"$MODULES_DIR\"." >&2 ; return 1 ;}
 
   # Update hardcoded path to directory with modules
   sed -i "s@/usr/share/bash-modules@$MODULES_DIR@g" "$BIN_DIR/import.sh" \

bash-modules/src/bash-modules/meta.sh

@@ -52,3 +52,33 @@ function $FUNCTION_NAME() {
 meta::functions_with_prefix() {
   compgen -A function "$1"
 }
+
+#>>
+#>> * meta::is_function FUNC_NAME Checks is given name corresponds to a function.
+meta::is_function() {
+  declare -F "$1" >/dev/null
+}
+
+#>>
+#>> * meta::dispatch PREFIX COMMAND [ARGUMENTS...] - execute function `PREFIX__COMMAND [ARGUMENTS]`
+#>
+#> For example, it can be used to execute functions (commands) by name, e.g.
+#> `main() { meta::dispatch command__ "$@" ; }`, when called as `man hw world` will execute
+#> `command_hw "$world"`. When command handler function is not found, dispatcher will try
+#> to call `PREFIX__DEFAULT` function instead, or return error code, if defaulf handler is not found.
+meta::dispatch() {
+  local prefix="${1:?Prefix is required.}"
+  local command="${2:?Command is required.}"
+  shift 2
+
+  local fn="${prefix}${command}"
+
+  # Is handler function exists?
+  meta::is_function "$fn" || {
+    # Is default handler function exists?
+    meta::is_function "${prefix}__DEFAULT" || { echo "ERROR: Function \"$fn\" is not found." >&2; return 1; }
+    fn="${prefix}__DEFAULT"
+  }
+
+  "$fn" "${@:+$@}" || return $?
+}

bash-modules/test/test_meta.sh

@@ -61,4 +61,56 @@ pr_3"
   unit::assert_equal "$output" "$expected_output" "Unexpected output from meta::functions_with_prefix."
 }
 
+test_is_function() {
+  unit::assert "is_function FUNCTION must return true" meta::is_function test_is_function
+  unit::assert "is_function FUNCTION must return true" meta::is_function meta::is_function
+
+  local a_var="foo"
+  unit::assert "is_function VAR must return false" ! meta::is_function a_var
+
+  unit::assert "is_function SHELL_BUILTIN must return false" ! meta::is_function cd
+  unit::assert "is_function COMMAND must return false" ! meta::is_function /usr/bin/ls
+}
+
+test_dispatch() {
+
+  local fresult=""
+
+  f1() {
+    fresult="f1 $*"
+  }
+  f2() {
+    fresult="f2 $*"
+  }
+
+  meta::dispatch f 1 foo bar || unit::fail "Cannot dispatch to function."
+  unit::assert_equal "$fresult" "f1 foo bar" "Unexpected result of call to f1 via dispatch."
+
+  meta::dispatch f 2 bar baz || unit::fail "Cannot dispatch to function."
+  unit::assert_equal "$fresult" "f2 bar baz" "Unexpected result of call to f2 via dispatch."
+
+  meta::dispatch f 3 bar baz 2>/dev/null && unit::fail "Dispatch function must not call an non-existing function or a command." || :
+  meta::dispatch l s bar baz 2>/dev/null && unit::fail "Dispatch function must not call an non-existing function or a command." || :
+  meta::dispatch c d bar baz 2>/dev/null && unit::fail "Dispatch function must not call an non-existing function or a command." || :
+}
+
+
+test_dispatch_with_default_handler() {
+
+  local fresult=""
+
+  f1() {
+    fresult="f1 $*"
+  }
+  f__DEFAULT() {
+    fresult="fD $*"
+  }
+
+  meta::dispatch f 1 foo bar || unit::fail "Cannot dispatch to function."
+  unit::assert_equal "$fresult" "f1 foo bar" "Unexpected result of call to f1 via dispatch."
+
+  meta::dispatch f 2 bar baz || unit::fail "Cannot dispatch to function."
+  unit::assert_equal "$fresult" "fD bar baz" "Unexpected result of call to f__DEFAULT via dispatch."
+}
+
 unit::run_test_cases "$@"